From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Graph comparing the increase in effective radius with speed for two different tyre types, alongside a discussion on tyre noise.
| Identifier | ExFiles\Box 45\2\ Scan013 | |
| Date | 1st January 1927 guessed | |
| contd :- -10- INCREASE IN RADIUS - INCHES Graph text: INCREASE IN EFFECTIVE RADIUS OF 33 X 6.75 DUNLOP CORD BALLOON TYRE LOAD ON TYRE - 1120 LBS. INFLATION PRESSURE 30 LBS/SQ.IN. 33 X 5 TYRE INFLATED TO 70 LBS SQ.IN. CARRYING 1320 LBS LOAD SPEED - M.P.H. (b) The question of noise: On a large car, tyre noise is a serious proposition. It is an unfortunate fact that if a tyre tread has good non-skid properties it will almost inevitably be noisy. Thus plain ribbed tyres are almost silent, traction tread inter-mediate, and triple stud produce quite an objectionable volume of sound. The main drawback to the triple stud is that the note it produces is singularly like that of a noisy rear axle. Balloon tyres usually have a lower note than the corresponding high pressure tyres but are very much more audible; it is advisable that contd :- | ||